Atmospheric Concentrations and Emissions of Major HFCs at Six Background Stations in China during 2012–2023

In this study, a long-term atmospheric observation of HFC-23, -32, -125, -134a, -143a, and -152a was conducted at six background stations across China from 2011 to 2023. Using a tracer ratio method with HCFC-22 as the reference, emissions from four main economic regions, Northeast Plain (NEP), North China Plain (NCP), Yangtze River Delta (YRD), and Central South China (CSC), were estimated, and their trends were analyzed over four phases: Phase 1 (2012–2016), Phase 2 (2017–2018), Phase 3 (2019–2020), and Phase 4 (2021–2023). The results show that from 2011 to 2023, the atmospheric mixing ratios of all studied HFCs except HFC-152a exhibited increasing trends. Nationally, emissions of HFC-23 show a decreasing tendency during Phase 4, while emissions of HFC-32, -125, -134a, and -143a continued to rise throughout Phases 3 and 4. These four HFCs were identified as the dominant species, accounting for over 76% of total HFCs’ mass emissions. From Phase 3 to Phase 4, CO2-equivalent HFC emissions per capita increased slightly, whereas emissions per unit GDP decreased, which is mainly attributable to significant HFC reductions in the CSC region. Nevertheless, China’s average HFC emission intensities (whether calculated per unit GDP or per capita) remain approximately 1.5–1.6 times the global average.